Sintering machine

ABSTRACT

A sintering machine including a travelling grate formed by a plurality of pallets which are moved along an endless path defined by an upper and a lower support portion connected at the discharge end of the machine by an arcuate portion. The pallets are pushed along the upper support portion toward the discharge end, and the pallets are arranged end-to-end with the exception of the safety gap between the pallets which are at any instant at the junction of the end of the upper support portion and the arcuate portion adjacent thereto. Means are provided which engage the pallet located at any instant upstream of the safety gap for smoothly moving the pallet into engagement with the pallet downstream of the gap.

United States Patent Stanke 1 May 30, 1972 [54] SINTERING MACHINE2,364,586 12 1944 Morgan ..266/2l 1,764,696 6/1930 Shallock........266/21 [72] Invent wane Stank Essen Germany 3,102,153 8/1963 Steileret al ..266/21 [73] Assignee: Heinrich Koppers Gesellschaft mitbeschrankter Haftung, Essen, Germany Primary ExaminerGerald A. DostFiled: y 1970 Attorney-Michael S. Striker Appl. No.: 39,057

[30] Foreign Application Priority Data May 30, 1969 Germany ..P 19 27537.7

[52] US. Cl ..266/21 [51] int. Cl ..F27b 21/06 [58] Field of Search..75/3, 5, 6, 7; 266/20, 21

[56] References Cited UNITED STATES PATENTS 3,201,102 8/1965 Stieler eta1 ..226/21 3,141,544 7/1964 Hansen ..'.266/21 [5 7] ABSTRACT Asintering machine including a travelling grate formed by a plurality ofpallets which are moved along an endless path defined by an upper and alower support portion connected at the discharge end of the machine byan arcuate portion. The pallets are pushed along the upper supportportion toward the discharge end, and the pallets are arrangedend-to-end with the exception of the safety gap between the palletswhich are at any instant at the junction of the end of the upper supportportion and the arcuate portion adjacent thereto. Means are providedwhich engage the pallet located at any instant upstream of the safetygap for smoothly moving the pallet into engagement with the palletdownstream of the gap.

10 Claims, 2 Drawing Figures SINTERING MACHINE BACKGROUND OF THEINVENTION The present invention relates to a sintering machine with atravelling grate formed by a plurality of pallets which are moved alongan endless path defined by an upper and a lower support portionconnected at the discharge end of the machine by an arcuate portion andin which the pallets are moved in a known manner at the inlet end of thegrate by a sprocket wheel engaging the pallets so as to push the same inabutting relationship along the upper support portion towards thedischarge end of the machine at which the pallets are guided by thearcuate support portion connecting the upper to the lower supportportion onto the latter.

Since the pallets which support the hot sintering material will expandduring operation of the machine in longitudinal direction thereof, thatis in the direction of the movement of the pallets, it is necessary tomaintain at the discharge end of the sintering machine, that is at thetransition of the upper support portion to the arcuate support portion asufficient safety gap between the pallet upstream of the transitionpoint, that is the last pallet of the end-to-end arranged pallets whichare pushed toward the discharge end of the machine and the first palletdownstream of the transition point which are already supported on thearcuate portion at the discharge end of the machine. This results insintering machines according to the prior art in the disadvantage that arelatively large safety gap had to be maintained at the start of themachine until, due to heat expansion of the pallets during the operationof the machine, this safety gap was shrinking to the desired width.Changes of the gap width may also occur during operation of the machinewhenever the machine is stopped for a shorter or longer period wherebythe temperature of the pallets will be changed so that the same will besubjected to a change of length.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide, in a sintering machine of the aforementioned kind in which asafety gap is provided between adjacent pallets at the discharge end ofthe machine, means preventing during operation of the machine the palletupstream of the safety gap to engage the pallet downstream of the safetygap with an impact.

It is a further object of the present invention to provide for anarrangement in which the safety gap may be maintained substantially at apredetermined width, regardless of the heat expansion of the palletchain.

It is an additional object of the present invention to provide for anarrangement of the aforementioned kind which is composed of relativelyfew and simple parts so that the arrangement will operate trouble-freeunder extended use.

With these and other objects in view, which will be evident from thefollowing description, the present invention mainly comprises asintering machine including an elongated travelling grate comprising aplurality of pallet means and support means supporting the pallet meansfor movement along an endless path having an upper support portion, alower support portion and an arcuate portion connecting the upper to thelower support portion at the discharge and of the machine, the palletmeans being pushed in one direction along the upper support portiontoward the discharge end thereof so as to abut with opposite endsagainst each other to thus form an endless grate with the exception of asafety gap arranged at the junction of the upper support portion to thearcuate portion permitting expansion of the grate, and means engagingthe pallet means which at any instant is upstream of the safety gap formoving this pallet means without any jolt into engagement with thepallet means downstream of the gap.

Preferably, the arcuate portion at the discharge end of the machine andthe engaging means are movable in longitudinal direction of the grate.

The aforementioned engaging means may be constructed in variousdifferent ways. In a preferred arrangement according to the presentinvention, the engaging means comprises wheel means rotatable about anaxis substantially normal to the longitudinal direction of the grate andhaving circumferentially spaced radially projecting portions adapted toengage into pocket means provided on each of the pallet means.

While it is possible to provide the wheel means of the engaging meanswith a positive drive rotating in synchronism with a driven or sprocketwheel located in the region of the inlet end of the machine andcooperating with the pallet means to push the latter along the uppersupport portion toward the discharge end of the machine, it has beenascertained that such a positive drive of the engaging means is notnecessary. According to a preferred arrangement of the presentinvention, the wheel means of the engaging means are moved only byengagement with the pallet means at the discharge end of the machine andin such an arrangement'the wheel means of the engaging means are brakedto assure a smooth transfer of the pallet means upstream of the gap ontothe pallet means downstream thereof.

The engaging means according to the present invention will thus preventimpact of the pallets against each other so that wear on the arcuateportion of the support, the wheels, the axles and the pallets per sewill be reduced. The engaging means will further assure a proper guidingof the pallets at the discharge end of the machine, which by theengaging means will be properly aligned in the direction of movement ofthe grate. In other words, the engaging means at the discharge end ofthe machine will have in this respect the same function as the liftingor sprocket wheels at the inlet or drive end of the grate.

Since, as already mentioned, the engaging means together with thearcuate support portion at the discharge end of the machine areadjustable in longitudinal direction of the grate, it is possible toadjust the desired width of the safety gap.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic partial side viewillustrating the discharge end of the sintering machine according to thepresent invention; and

FIG. 2 is a schematic view of the braking means connected to theengaging means of the machine according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates thedischarge end of the sintering machine according to the presentinvention. As can be seen from FIG. 1, the pallets 2 of the travellinggrate of the sintering machines are moved on the upper support or trackportion 1 of the machine in end-to-end abutting relationship in thedirection of the arrow 1: by conventional means, for instance sprocketwheels driven by a prime mover at the inlet end of the machine andcooperating with pockets 14 respectively provided on opposite sides andin the bottom region of each pallet. These drive means are conventionaland are therefore not shown in the drawing. A cam portion 3 is providedat the left end, as viewed in FIG. 1, of the upper horizontal trackportion 1 over which the wheels 4 of the pallets 2 have to be pushedbefore the pallets may move downwardly by gravity over the inclinedportion 6 of the support or track means which is fixedly connected toand forms part of the arcuate connecting portion 5 which leads from theupper horizontally arranged support or track portion 1 to the lowersupport or track portion 1'. The latter, as shown in FIG. 1, is slightlyinclined toward the right or inlet end of the sintering machine. Betweenthe last pallet 2' of the pushed end-to-end abutting pallet chain andthe first pallet 2" which moves downwardly under the influence ofgravity on the inclined track portion 6 is a safety gap 7, the width ofwhich may vary during the operation of the machine, which however shouldbe maintained substantially at a predetermined width at this transitionpoint. It is to be understood that pallets are arranged end-toend on theconnecting portion and the lower track portion 1, but for simplificationreason these pallets are not shown in the drawing.

To prevent impact of the pallet 2' onto the pallet 2", engaging means 8are provided in the region of the safety gap 7. The engaging means 8 maycomprise a pair of wheels 9, only the front one being shown in thedrawing, which are: fixed to a shaft 10 having an axis normal to thedirection of movement of the pallets 2. The shaft 10 is mounted onbearings 11 and the latter are supported on a frame including uprightstruts 17 which also support the inclined track portion 6 and thearcuate track portion 5. The lower ends of the struts 17 are fixedlyconnected to a carriage 18, having wheels 16 which are mounted on shortrail portions 19 for movement in longitudinal direction of the grateformed by the pallets 2. Fixed abutment means 20 are respectivelyprovided adjacent to, but spaced from, opposite ends of the carriage l8and a plurality of spacer plates 21 are sandwiched between face portionsof the abutment means 20 and the respective opposite ends of thecarriage 18 so as to hold the carriage 18, the frame supported therebyand the engaging means 8 as well as the track portions'S and 6 in apredetermined position relative to the stationary upper and lower trackportions 1 and 1'. By removing one or a plurality of the spacer plates21 from one of the ends of the carriage 18, the latter may be slightlymoved in longitudinal direction to one side or the other and by theninserting the spacer plate or plates between the other end of thecarriage 18 and the abutment means 20 adjacent thereto, the carriage 18and the elements supported thereby may then be fixed again in the thusadjusted position.

In the illustrated embodiment each of the wheels 9 of the engaging meanshas five circumferentially spaced radially projecting portions or arms12 each of which carries at the outer end thereof a roller 13. The armsand the rollers thereon are dimensioned in such a manner that they mayengage with ample clearance into the pockets 14 provided on the pallets2. In the position of the various elements shown in the drawing, the arm12" is ready to move out of the pocket 14" of the pallet 2" after thelatter has moved in abutment relationship with the preceding pallet 2".At the same time, the arm 12' enters into the pocket 14 of the pallet 2'upstream of the safety gap 7 without, however, yet engaging the rightside wall 15 of the pocket. Only after the pallet 2 is slightly pushedfurther in the direction of the arrow x will the aforementioned sidewall of the pocket 14 bear against the roller on the arm 12' to therebyturn the latter together with the wheel 9 in counterclockwise direction.As soon as the rear wheel of the pallet 2 has past the cam portion 3, itwill move under the influence of gravity downwardly along the inclinedtrack portion 6 and would therefore engage the pallet 2' with aconsiderable impact. To prevent such an impact, braking means areconnected to the engaging means 8 to brake rotation of the latter tothereby brake movement of the pallet 2 and to assure abutment of thelatter against the pallet 2" without any jolt or impact.

Such braking means may include an oil pump 22 fixed to the shaft 10 forrotation therewith, a closed conduit loop 23 through which the oilpumped by the pump 22 is circulated and in which throttling means 24 areprovided, which are preferably adjustable, so that the force necessaryto drive the oil through the throttling means 24 of the closed circuitwill provide a braking force on the wheel 9.

As mentioned before, the size of the safety gap 7 will vary duringoperation of the machine and will mainly depend on the temperature ofthe pallets. Preferably, the arrangement according to the presentinvention includes therefore also measuring means for continuouslymeasuring the width of the safety gap 17. Such measuring means may forinstance include a pair of contact means 25 and 25' stationarily mountedby means not shown in the drawing at a distance from each other tosimultaneously engage portions, for instance projecting shaft portionsof the rear wheels of the pallets, to opposite sides of the safety gap 7when the latter has a predetermined width. These contact means may beconnected in a known manner, not forming part of the present invention,in circuit with an indicating or signal device in such a manner that thelatter will not be energized when both contact means are simultaneouslyactuated, that is when the safety gap 7 has its predetermined width, butto actuate the signal device in one or the other way whenever thecontact 25 is actuated either before or after actuation of the contact25, to thereby indicate that the width of the safety gap is smaller,respectively larger than the predetermined width. When such a signaloccurs, the operator may adjust the safety gap and the position of theengaging means 8 by changing the position of the carriage 18 in themanner as described before.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types of asintering machine differing from the types described above.

While the invention has been illustrated and described as embodied in asintering machine provided with a safety gap in the pallet chain formingthe grate of the sintering machine and with means assuring a smoothtransition of the pallets through the safety gap, it is not intended tobe limited to the details shown, since various modifications andstructural changes may be made without departing in any way from thespirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended 1. In a sintering machine, a combinationcomprising an elongated travelling grate having a discharge end andcompris ing a plurality of pallet means and support means supportingsaid pallet means for movement along an endless path defined by an uppersupport portion, a lower support portion, and an at least partly curvedconnecting portion connecting said upper to said lower support portionat said discharge end, said pallet means being pushed in one directionalong said upper support portion toward said discharge end so as to abutwith opposite ends against each other with the exception of a safety gaparranged in the region of the junction of said upper support portion andsaid connecting portion; and means engaging that pallet means which atany instance is upstream of said gap for moving said pallet meanswithout any jolt into engagement with the pallet means downstream ofsaid gap, while becoming disengaged from said pallet means downstream ofsaid gap so as to free the downstream pallet means for movementexclusively under the influence of gravity along said connecting portiononto said lower support portion.

2. A combination as defined in claim 1, and including mounting meansmounting said connecting portion and said engaging means movable inlongitudinal direction of said grate relative to the upper and lowersupport portions.

3. A combination as defined in claim 2, wherein said mounting meanscomprise a carriage having opposite ends, stationary means mounting saidcarriage movable in longitudinal direction of said grate, a pair ofabutment means on said stationary means respectively arranged spacedfrom and facing said opposite ends of said carriage, and a plurality ofspacer means selectively insertable between said abutment means and saidopposite ends of said carriage for adjusting the position of the latterwith respect to the stationary means and therewith the position of saidengaging means and that of said connecting portion.

4. A combination as defined in claim 1, and including pocket means oneach of said pallet means, said engaging means comprising wheel meansrotatable about an axis substantially normal to the longitudinaldirection of said grate and having circumferentially spaced radiallyprojecting portions adapted to engage into said pocket means of saidpallet means.

5. A combination as defined in claim 4, wherein said pocket means areopen at the bottom thereof, and wherein said axis of said wheel means isarranged in a plane substantially parallel and at an elevation belowthat of said upper support portion.

6. A combination as defined in claim 4, wherein said wheel means areturned about the axis thereof only by engagement of said projectingportions thereof with said pocket means, and including means cooperatingwith said wheel means for braking rotation thereof about said axis.

7. A combination as defined in claim 6, wherein said braking meanscomprise pump means connected to said wheel means for rotationtherewith, endless conduit means connected to said pump means forcirculating liquid therethrough during operation of said pump means, andthrottling means in said conduit means for throttling passage of theliquid therethrough.

8. In a sintering machine, a combination comprising an elongatedtravelling grate having a discharge end and comprising a plurality ofpallet means and support means supporting said pallet means for movementalong an endless path defined by an upper support portion, a lowersupport portion and an at least partly curved connecting portionconnecting said upper to said lower support portion at said dischargeend, said pallet means being pushed in one direction along said uppersupport portion toward said discharge end so as to abut with saidopposite ends against each other with the exception of a safety gaparranged in the region of the junction of said upper support portion andsaid connecting portion, each of said pallet means having pocket meansopen at the bottom thereof; and means engaging that pallet means whichat any instance is upstream of said gap for moving said pallet meanswithout any jolt into engagement with the pallet means downstream ofsaid gap, said engaging means comprising wheel means rotatable about anaxis substantially normal to the longitudinal direction of said grate ina plane substantially parallel and at an elevation below that of saidupper support means and having circumferentially spaced radiallyprojecting arms each carrying a roller at the outer free ends thereofadapted to engage into said pockets means said pallet means. i

9. In a sintering machine, a combination comprising an elongatedtravelling grate having a discharge end and comprising a plurality ofpallet means and support means supporting said pallet means for movementalong an endless path defined by an upper support portion, a lowersupport portion and an at least partly curved connecting portionconnecting said upper to said lower support portion at said dischargeend, said pallet means being pushed in one direction along said uppersupport portion toward said discharge end so as to abut with oppositeends against each other with the exception of a safety gap arranged inthe region of the junction of said upper support portion and saidconnecting portion; and means engaging that pallet means which at anyinstance is upstream of said gap for moving said pallet means withoutany jolt into engagement with the pallet means downstream of said gapand comprising rotatable wheel means having projecting portions adaptedto engage with said pallet means, braking means cooperating with saidwheel means for braking its rotation, said braking means comprising pumpmeans connected to said wheel means for rotation therewith, endlessconduit means connected to said pump means for circulating fluid liquidtherethrough during operation of said pump means, and throttling meansin said conduit means for throttling passage of the liquid therethrough.

10. In a sintering machine, a combination, comprising an elongatedtravellingafirate having a discharge end and comprising a plurality of pet means and support means supporting said pallet means for movementalong an endless path, defined by an upper support portion, a lowersupport portion, and an at least partly curved connecting portionconnecting said upper to said lower support portion at said dischargeend, said pallet means being pushed in one direction along said uppersupport portion toward said discharge end so as to abut with oppositeends against each other with the exception of a safety gap arranged inthe region of the junction of said upper support portion and saidconnecting portion; means engaging that pallet means which at anyinstance is upstream of said gap for moving said pallet means withoutany jolt into engagement with the pallet means downstream of said gap;mounting means mounting said connecting portion and said engaging meansmovable in longitudinal direction of said grate relative to the upperand lower support portions; and means for continuously measuring thesize of said safety gap and for indicating whenever said gap deviatesessentially from a predetermined size so that said engaging means andsaid connecting portion may be moved in longitudinal direction of saidgrate to adjust said gap.

1. In a sintering machine, a combination comprising an elongatedtravelling grate having a discharge end and comprising a plurality ofpallet means and support means supporting said pallet means for movementalong an endless path defined by an upper support portion, a lowersupport portion, and an at least partly curved connecting portionconnecting said upper to said lower support portion at said dischargeend, said pallet means being pushed in one direction along said uppersupport portion toward said discharge end so as to abut with oppositeends against each other with the exception of a safety gap arranged inthe region of the junction of said upper support portion and saidconnecting portion; and means engaging that pallet means which at anyinstance is upstream of said gap for moving said pallet means withoutany jolt into engagement with the pallet means downstream of said gap,while becoming disengaged from said pallet means downstream of said gapso as to free the downstream pallet means for movement exclusively underthe influence of gravity along said connecting portion onto said lowersupport portion.
 2. A combination as defined in claim 1, and includingmounting means mounting said connecting portion and said engaging meansmovable in longitudinal direction of said grate relative to the upperand lower support portions.
 3. A combination as defined in claim 2,wherein said mounting means comprise a carriage having opposite ends,stationary means mounting said carriage movable in longitudinaldirection of said grate, a pair of abutment means on said stationarymeans respectively arranged spaced from and facing said opposite ends ofsaid carriage, and a plurality of spacer means selectively insertablebetween said abutment means and said opposite ends of said carriage foradjusting the position of the latter with respect to the stationarymeans and therewith the position of said engaging means and that of saidconnecting portion.
 4. A combination as defined in claim 1, andincluding pocket means on each of said pallet means, said engaging meanscomprising wheel means rotatable about an axis substantially normal tothe longitudinal direction of said grate and having circumferentiallyspaced radially projecting portions adapted to engage into said pocketmeans of said pallet means.
 5. A combination as defined in claim 4,wherein said pocket means are open at the bottom thereof, and whereinsaid axis of said wheel means is arranged in a plane substantiallyparallel and at an elevation below that of said upper support portion.6. A combination as defined in claim 4, wherein said wheel means areturned about the axis thereof only by engagement of said projectingportions thereof with said pocket means, and including means cooperatingwith said wheel means for braking rotation thereof about said axis.
 7. Acombination as defined in claim 6, wherein said braking means comprisepump means connected to said wheel means for rotation therewith, endlessconduit means connected to said pump means for circulating liquidtherethrough during operation of said pump means, and throttling meansin said conduit means for throttling passage of the liquid therethrough.8. In a sintering machine, a combination comprising an elongatedtravelling grate having a discharge end and comprising a plurality ofpallet means and support means supporting said pallet means for movementalong an endless path defined by an upper support portion, a lowersupport portion and an at least partly curved connecting portionconnecting said upper to said lower support portion at said dischargeend, said pallet means being pushed in one direction along said uppersupport portion toward said discharge end so as to abut with saidopposite ends against each other with the exception of a safety gaparranged in the region of the junction of said upper support portion andsaid connecting portion, each of said pallet means having pocket meansopen at the bottom thereof; and means engaging that pallet means whichat any instance is upstream of said gap for moving said pallet meanswithout any jolt into engagement with the pallet means downstream ofsaid gap, said engaging means comprising wheel means rotatable about anaxis substantially normal to the longitudinal direction of said grate ina plane substantially parallel and at an elevation below that of saidupper support means and having circumferentially spaced radiallyprojecting arms each carrying a roller at the outer free ends thereofadapted to engage into said pockets means said pallet means.
 9. In asintering machine, a combination comprising an elongated travellinggrate having a discharge end and comprising a plurality of pallet meansand support means supporting said pallet means for movement along anendless path defined by an upper support portion, a lower supportportion and an at least partly curved connecting portion connecting saidupper to said lower support portion at said discharge end, said palletmeans being pushed in one direction along said upper support portiontoward said discharge end so as to abut with opposite ends against eachother with the exception of a safety gap arranged in the region of thejunction of said upper support portion and said connecting portion; andmeans engaging that pallet means which at any instance is upstream ofsaid gap for moving said pallet means without any jolt into engagementwith the pallet means downstream of said gap and comprising rotatablewheel means having projecting portions adapted to engage with saidpallet means, braking means cooperating with said wheel means forbraking its rotation, said braking means comprising pump means connectedto said wheel means for rotation therewith, endless conduit meansconnected to said pump means for circulating fluid liquid therethroughduring operation of said pump means, and throttling means in saidconduit means for throttling passage of the liquid therethrough.
 10. Ina sintering machine, a combination, comprising an elongated travellinggrate having a discharge end and comprising a plurality of pallet meansand support means supporting said pallet means for movement along anendless path, defined by an upper support portion, a lower supportportion, and an at least partly curved connecting portion connectingsaid upper to said lower support portion at said discharge end, saidpallet means being pushed in one direction along said upper supportportion toward said discharge end so as to abut with opposite endsagainst each other with the exception of a safety gap arranged in theregion of the junction of said upper support portion and said connectingportion; means engaging that pallet means which at any instance isupstream of said gap for moving said pallet means without any jolt intoengagement with the pallet means downstream of said gap; mounting meansmounting said connecting portion and said engaging means movable inlongitudinal direction of said grate relative to the upper and lowersupport portions; and means for continuously measuring the size of saidsafety gap and for indicating whenever said gap deviates essentiallyfrom a predetermined size so that said engaging means and saidconnecting portion may be moved in longitudinal direction of said grateto adjust said gap.